Proper handling of null values on GetOrSet methods

raphaabreu · Oct 15, 2020 · c099c74 · c099c74
1 parent 5ea7569
commit c099c74
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Showing 11 changed files with 130 additions and 87 deletions.
diff --git a/samples/Sample.Application/WeatherService.cs b/samples/Sample.Application/WeatherService.cs
@@ -13,6 +13,12 @@ public class WeatherService : IWeatherService
 
         public async Task<WeatherForecast> FetchForecastAsync(DateTime date, CancellationToken cancellationToken)
         {
+            // Value factories that return null don't get cached by GetOrSet extensions.
+            if (RNG.NextDouble() > 0.5)
+            {
+                return null;
+            }
+
             // Simulate access to a database or third party service.
             await Task.Delay(100, cancellationToken);
 

diff --git a/...oncepts.Extensions.Caching.Abstractions/Distributed/DistributedCacheGetOrSetExtensions.cs b/...oncepts.Extensions.Caching.Abstractions/Distributed/DistributedCacheGetOrSetExtensions.cs
@@ -20,19 +20,19 @@ public static Task SetAsync(this IDistributedCache cache, string key, byte[] val
         }
 
 
-        public static byte[] GetOrSet(this IDistributedCache cache, string key, Func<byte[]> valueFactory)
+        public static byte[]? GetOrSet(this IDistributedCache cache, string key, Func<byte[]?> valueFactory)
         {
             return cache.GetOrSet(key, valueFactory, new DistributedCacheEntryOptions());
         }
 
-        public static byte[] GetOrSet(this IDistributedCache cache, string key, Func<byte[]> valueFactory,
+        public static byte[]? GetOrSet(this IDistributedCache cache, string key, Func<byte[]?> valueFactory,
             TimeSpan absoluteExpirationRelativeToNow)
         {
             return cache.GetOrSet(key, valueFactory,
                 new DistributedCacheEntryOptions { AbsoluteExpirationRelativeToNow = absoluteExpirationRelativeToNow });
         }
 
-        public static byte[] GetOrSet(this IDistributedCache cache, string key, Func<byte[]> valueFactory,
+        public static byte[]? GetOrSet(this IDistributedCache cache, string key, Func<byte[]?> valueFactory,
             DistributedCacheEntryOptions options)
         {
             var cached = cache.Get(key);
@@ -44,26 +44,29 @@ public static byte[] GetOrSet(this IDistributedCache cache, string key, Func<byt
 
             var value = valueFactory();
 
-            cache.Set(key, value, options);
+            if (value != null)
+            {
+                cache.Set(key, value, options);
+            }
 
             return value;
         }
 
 
-        public static Task<byte[]> GetOrSetAsync(this IDistributedCache cache, string key, Func<Task<byte[]>> valueFactory,
+        public static Task<byte[]?> GetOrSetAsync(this IDistributedCache cache, string key, Func<Task<byte[]?>> valueFactory,
             CancellationToken token = default)
         {
             return cache.GetOrSetAsync(key, valueFactory, new DistributedCacheEntryOptions(), token);
         }
 
-        public static Task<byte[]> GetOrSetAsync(this IDistributedCache cache, string key, Func<Task<byte[]>> valueFactory,
+        public static Task<byte[]?> GetOrSetAsync(this IDistributedCache cache, string key, Func<Task<byte[]?>> valueFactory,
             TimeSpan absoluteExpirationRelativeToNow, CancellationToken token = default)
         {
             return cache.GetOrSetAsync(key, valueFactory,
                 new DistributedCacheEntryOptions { AbsoluteExpirationRelativeToNow = absoluteExpirationRelativeToNow }, token);
         }
 
-        public static async Task<byte[]> GetOrSetAsync(this IDistributedCache cache, string key, Func<Task<byte[]>> valueFactory,
+        public static async Task<byte[]?> GetOrSetAsync(this IDistributedCache cache, string key, Func<Task<byte[]?>> valueFactory,
             DistributedCacheEntryOptions options, CancellationToken token = default)
         {
             var cached = await cache.GetAsync(key, token);
@@ -75,25 +78,28 @@ public static async Task<byte[]> GetOrSetAsync(this IDistributedCache cache, str
 
             var value = await valueFactory();
 
-            await cache.SetAsync(key, value, options, token);
+            if (value != null)
+            {
+                await cache.SetAsync(key, value, options, token);
+            }
 
             return value;
         }
 
 
-        public static string GetOrSetString(this IDistributedCache cache, string key, Func<string> valueFactory)
+        public static string? GetOrSetString(this IDistributedCache cache, string key, Func<string?> valueFactory)
         {
             return cache.GetOrSetString(key, valueFactory, new DistributedCacheEntryOptions());
         }
 
-        public static string GetOrSetString(this IDistributedCache cache, string key, Func<string> valueFactory,
+        public static string? GetOrSetString(this IDistributedCache cache, string key, Func<string?> valueFactory,
             TimeSpan absoluteExpirationRelativeToNow)
         {
             return cache.GetOrSetString(key, valueFactory,
                 new DistributedCacheEntryOptions { AbsoluteExpirationRelativeToNow = absoluteExpirationRelativeToNow });
         }
 
-        public static string GetOrSetString(this IDistributedCache cache, string key, Func<string> valueFactory,
+        public static string? GetOrSetString(this IDistributedCache cache, string key, Func<string?> valueFactory,
             DistributedCacheEntryOptions options)
         {
             var cached = cache.GetString(key);
@@ -105,27 +111,30 @@ public static string GetOrSetString(this IDistributedCache cache, string key, Fu
 
             var value = valueFactory();
 
-            cache.SetString(key, value, options);
+            if (value != null)
+            {
+                cache.SetString(key, value, options);
+            }
 
             return value;
         }
 
 
-        public static Task<string> GetOrSetStringAsync(this IDistributedCache cache, string key,
-            Func<Task<string>> valueFactory, CancellationToken token = default)
+        public static Task<string?> GetOrSetStringAsync(this IDistributedCache cache, string key,
+            Func<Task<string?>> valueFactory, CancellationToken token = default)
         {
             return cache.GetOrSetStringAsync(key, valueFactory, new DistributedCacheEntryOptions(), token);
         }
 
-        public static Task<string> GetOrSetStringAsync(this IDistributedCache cache, string key,
-            Func<Task<string>> valueFactory, TimeSpan absoluteExpirationRelativeToNow, CancellationToken token = default)
+        public static Task<string?> GetOrSetStringAsync(this IDistributedCache cache, string key,
+            Func<Task<string?>> valueFactory, TimeSpan absoluteExpirationRelativeToNow, CancellationToken token = default)
         {
             return cache.GetOrSetStringAsync(key, valueFactory,
                 new DistributedCacheEntryOptions { AbsoluteExpirationRelativeToNow = absoluteExpirationRelativeToNow }, token);
         }
 
-        public static async Task<string> GetOrSetStringAsync(this IDistributedCache cache, string key,
-            Func<Task<string>> valueFactory, DistributedCacheEntryOptions options, CancellationToken token = default)
+        public static async Task<string?> GetOrSetStringAsync(this IDistributedCache cache, string key,
+            Func<Task<string?>> valueFactory, DistributedCacheEntryOptions options, CancellationToken token = default)
         {
             var cached = await cache.GetStringAsync(key, token);
 
@@ -136,7 +145,10 @@ public static async Task<string> GetOrSetStringAsync(this IDistributedCache cach
 
             var value = await valueFactory();
 
-            await cache.SetStringAsync(key, value, options, token);
+            if (value != null)
+            {
+                await cache.SetStringAsync(key, value, options, token);
+            }
 
             return value;
         }

diff --git a/...pleConcepts.Extensions.Caching.Abstractions/Distributed/DistributedCacheJsonExtensions.cs b/...pleConcepts.Extensions.Caching.Abstractions/Distributed/DistributedCacheJsonExtensions.cs
@@ -35,50 +35,50 @@ public static class DistributedCacheJsonExtensions
 
 
 
-        public static void SetJsonObject<T>(this IDistributedCache cache, string key, T? value,
+        public static void SetJsonObject<T>(this IDistributedCache cache, string key, T value,
             JsonSerializerOptions? serializerOptions = null) where T : class
         {
             cache.SetJsonObject(key, value, new DistributedCacheEntryOptions(), serializerOptions);
         }
 
-        public static void SetJsonObject<T>(this IDistributedCache cache, string key, T? value,
+        public static void SetJsonObject<T>(this IDistributedCache cache, string key, T value,
             TimeSpan absoluteExpirationRelativeToNow, JsonSerializerOptions? serializerOptions = null) where T : class
         {
             cache.SetJsonObject(key, value,
                 new DistributedCacheEntryOptions { AbsoluteExpirationRelativeToNow = absoluteExpirationRelativeToNow },
                 serializerOptions);
         }
 
-        public static void SetJsonObject<T>(this IDistributedCache cache, string key, T? value,
+        public static void SetJsonObject<T>(this IDistributedCache cache, string key, T value,
             DistributedCacheEntryOptions entryOptions, JsonSerializerOptions? serializerOptions = null) where T : class
         {
-            var bytes = value != null ? JsonSerializer.SerializeToUtf8Bytes(value, serializerOptions) : null;
+            var bytes = JsonSerializer.SerializeToUtf8Bytes(value, serializerOptions);
 
             cache.Set(key, bytes, entryOptions);
         }
 
 
-        public static Task SetJsonObjectAsync<T>(this IDistributedCache cache, string key, T? value,
+        public static Task SetJsonObjectAsync<T>(this IDistributedCache cache, string key, T value,
             CancellationToken token = default) where T : class
         {
             return cache.SetJsonObjectAsync(key, value, new DistributedCacheEntryOptions(), null, token);
         }
 
-        public static Task SetJsonObjectAsync<T>(this IDistributedCache cache, string key, T? value,
+        public static Task SetJsonObjectAsync<T>(this IDistributedCache cache, string key, T value,
             JsonSerializerOptions? serializerOptions, CancellationToken token = default) where T : class
         {
             return cache.SetJsonObjectAsync(key, value, new DistributedCacheEntryOptions(), serializerOptions, token);
         }
 
-        public static Task SetJsonObjectAsync<T>(this IDistributedCache cache, string key, T? value,
+        public static Task SetJsonObjectAsync<T>(this IDistributedCache cache, string key, T value,
             TimeSpan absoluteExpirationRelativeToNow, CancellationToken token = default) where T : class
         {
             return cache.SetJsonObjectAsync(key, value,
                 new DistributedCacheEntryOptions { AbsoluteExpirationRelativeToNow = absoluteExpirationRelativeToNow },
                 null, token);
         }
 
-        public static Task SetJsonObjectAsync<T>(this IDistributedCache cache, string key, T? value,
+        public static Task SetJsonObjectAsync<T>(this IDistributedCache cache, string key, T value,
             TimeSpan absoluteExpirationRelativeToNow, JsonSerializerOptions? serializerOptions,
             CancellationToken token = default) where T : class
         {
@@ -87,33 +87,33 @@ public static Task SetJsonObjectAsync<T>(this IDistributedCache cache, string ke
                 serializerOptions, token);
         }
 
-        public static Task SetJsonObjectAsync<T>(this IDistributedCache cache, string key, T? value,
+        public static Task SetJsonObjectAsync<T>(this IDistributedCache cache, string key, T value,
             DistributedCacheEntryOptions entryOptions, JsonSerializerOptions? serializerOptions = null,
             CancellationToken token = default) where T : class
         {
-            var bytes = value != null ? JsonSerializer.SerializeToUtf8Bytes(value, serializerOptions) : null;
+            var bytes = JsonSerializer.SerializeToUtf8Bytes(value, serializerOptions);
 
             return cache.SetAsync(key, bytes, entryOptions, token);
         }
 
 
 
-        public static T GetOrSetJsonObject<T>(this IDistributedCache cache, string key, Func<T> valueFactory,
+        public static T? GetOrSetJsonObject<T>(this IDistributedCache cache, string key, Func<T?> valueFactory,
             JsonSerializerOptions? serializerOptions = null) where T : class
         {
             return cache.GetOrSetJsonObject(key, valueFactory, new DistributedCacheEntryOptions(), serializerOptions);
         }
 
 
-        public static T GetOrSetJsonObject<T>(this IDistributedCache cache, string key, Func<T> valueFactory,
+        public static T? GetOrSetJsonObject<T>(this IDistributedCache cache, string key, Func<T?> valueFactory,
             TimeSpan absoluteExpirationRelativeToNow, JsonSerializerOptions? serializerOptions = null) where T : class
         {
             return cache.GetOrSetJsonObject<T>(key, valueFactory,
                 new DistributedCacheEntryOptions { AbsoluteExpirationRelativeToNow = absoluteExpirationRelativeToNow },
                 serializerOptions);
         }
 
-        public static T GetOrSetJsonObject<T>(this IDistributedCache cache, string key, Func<T> valueFactory,
+        public static T? GetOrSetJsonObject<T>(this IDistributedCache cache, string key, Func<T?> valueFactory,
             DistributedCacheEntryOptions entryOptions, JsonSerializerOptions? serializerOptions = null) where T : class
         {
             var cached = cache.GetJsonObject<T>(key, serializerOptions);
@@ -125,50 +125,53 @@ public static T GetOrSetJsonObject<T>(this IDistributedCache cache, string key,
 
             var value = valueFactory();
 
-            cache.SetJsonObject(key, value, entryOptions, serializerOptions);
+            if (value != null)
+            {
+                cache.SetJsonObject(key, value, entryOptions, serializerOptions);
+            }
 
             return value;
         }
 
 
-        public static Task<T> GetOrSetJsonObjectAsync<T>(this IDistributedCache cache, string key,
-            Func<Task<T>> valueFactory, CancellationToken token = default) where T : class
+        public static Task<T?> GetOrSetJsonObjectAsync<T>(this IDistributedCache cache, string key,
+            Func<Task<T?>> valueFactory, CancellationToken token = default) where T : class
         {
             return cache.GetOrSetJsonObjectAsync(key, valueFactory, new DistributedCacheEntryOptions(), null, token);
         }
-        public static Task<T> GetOrSetJsonObjectAsync<T>(this IDistributedCache cache, string key,
-            Func<Task<T>> valueFactory, JsonSerializerOptions? serializerOptions,
+        public static Task<T?> GetOrSetJsonObjectAsync<T>(this IDistributedCache cache, string key,
+            Func<Task<T?>> valueFactory, JsonSerializerOptions? serializerOptions,
             CancellationToken token = default) where T : class
         {
             return cache.GetOrSetJsonObjectAsync(key, valueFactory, new DistributedCacheEntryOptions(), serializerOptions, token);
         }
 
-        public static Task<T> GetOrSetJsonObjectAsync<T>(this IDistributedCache cache, string key,
-            Func<Task<T>> valueFactory, TimeSpan absoluteExpirationRelativeToNow, JsonSerializerOptions? serializerOptions,
+        public static Task<T?> GetOrSetJsonObjectAsync<T>(this IDistributedCache cache, string key,
+            Func<Task<T?>> valueFactory, TimeSpan absoluteExpirationRelativeToNow, JsonSerializerOptions? serializerOptions,
             CancellationToken token = default) where T : class
         {
             return cache.GetOrSetJsonObjectAsync(key, valueFactory,
                 new DistributedCacheEntryOptions { AbsoluteExpirationRelativeToNow = absoluteExpirationRelativeToNow },
                 serializerOptions, token);
         }
 
-        public static Task<T> GetOrSetJsonObjectAsync<T>(this IDistributedCache cache, string key,
-            Func<Task<T>> valueFactory, TimeSpan absoluteExpirationRelativeToNow, CancellationToken token = default) where T : class
+        public static Task<T?> GetOrSetJsonObjectAsync<T>(this IDistributedCache cache, string key,
+            Func<Task<T?>> valueFactory, TimeSpan absoluteExpirationRelativeToNow, CancellationToken token = default) where T : class
         {
             return cache.GetOrSetJsonObjectAsync(key, valueFactory,
                 new DistributedCacheEntryOptions { AbsoluteExpirationRelativeToNow = absoluteExpirationRelativeToNow },
                 null, token);
         }
 
-        public static Task<T> GetOrSetJsonObjectAsync<T>(this IDistributedCache cache, string key,
-            Func<Task<T>> valueFactory, DistributedCacheEntryOptions entryOptions,
+        public static Task<T?> GetOrSetJsonObjectAsync<T>(this IDistributedCache cache, string key,
+            Func<Task<T?>> valueFactory, DistributedCacheEntryOptions entryOptions,
             CancellationToken token = default) where T : class
         {
             return cache.GetOrSetJsonObjectAsync<T>(key, valueFactory, entryOptions, null, token);
         }
 
-        public static async Task<T> GetOrSetJsonObjectAsync<T>(this IDistributedCache cache, string key,
-            Func<Task<T>> valueFactory, DistributedCacheEntryOptions entryOptions,
+        public static async Task<T?> GetOrSetJsonObjectAsync<T>(this IDistributedCache cache, string key,
+            Func<Task<T?>> valueFactory, DistributedCacheEntryOptions entryOptions,
             JsonSerializerOptions? serializerOptions = null, CancellationToken token = default) where T : class
         {
             var cached = await cache.GetJsonObjectAsync<T>(key, serializerOptions, token);
@@ -180,7 +183,10 @@ public static async Task<T> GetOrSetJsonObjectAsync<T>(this IDistributedCache ca
 
             var value = await valueFactory();
 
-            await cache.SetJsonObjectAsync(key, value, entryOptions, serializerOptions, token);
+            if (value != null)
+            {
+                await cache.SetJsonObjectAsync(key, value, entryOptions, serializerOptions, token);
+            }
 
             return value;
         }

diff --git a/src/SimpleConcepts.Extensions.Caching.Abstractions/IValueSerializer.cs b/src/SimpleConcepts.Extensions.Caching.Abstractions/IValueSerializer.cs
@@ -4,7 +4,7 @@ namespace SimpleConcepts.Extensions.Caching
 {
     public interface IValueSerializer
     {
-        byte[]? Serialize(object? value);
+        byte[] Serialize(object value);
         object? Deserialize(byte[]? bytes, Type type);
     }
 }